1 /*******************************************************************************
2  * Filename: target_core_xcopy.c
3  *
4  * This file contains support for SPC-4 Extended-Copy offload with generic
5  * TCM backends.
6  *
7  * Copyright (c) 2011-2013 Datera, Inc. All rights reserved.
8  *
9  * Author:
10  * Nicholas A. Bellinger <nab@daterainc.com>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  ******************************************************************************/
23 
24 #include <linux/slab.h>
25 #include <linux/spinlock.h>
26 #include <linux/list.h>
27 #include <linux/configfs.h>
28 #include <linux/ratelimit.h>
29 #include <scsi/scsi_proto.h>
30 #include <asm/unaligned.h>
31 
32 #include <target/target_core_base.h>
33 #include <target/target_core_backend.h>
34 #include <target/target_core_fabric.h>
35 
36 #include "target_core_internal.h"
37 #include "target_core_pr.h"
38 #include "target_core_ua.h"
39 #include "target_core_xcopy.h"
40 
41 static struct workqueue_struct *xcopy_wq = NULL;
42 
43 static sense_reason_t target_parse_xcopy_cmd(struct xcopy_op *xop);
44 
45 static int target_xcopy_gen_naa_ieee(struct se_device *dev, unsigned char *buf)
46 {
47 	int off = 0;
48 
49 	buf[off++] = (0x6 << 4);
50 	buf[off++] = 0x01;
51 	buf[off++] = 0x40;
52 	buf[off] = (0x5 << 4);
53 
54 	spc_parse_naa_6h_vendor_specific(dev, &buf[off]);
55 	return 0;
56 }
57 
58 struct xcopy_dev_search_info {
59 	const unsigned char *dev_wwn;
60 	struct se_device *found_dev;
61 };
62 
63 static int target_xcopy_locate_se_dev_e4_iter(struct se_device *se_dev,
64 					      void *data)
65 {
66 	struct xcopy_dev_search_info *info = data;
67 	unsigned char tmp_dev_wwn[XCOPY_NAA_IEEE_REGEX_LEN];
68 	int rc;
69 
70 	if (!se_dev->dev_attrib.emulate_3pc)
71 		return 0;
72 
73 	memset(&tmp_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
74 	target_xcopy_gen_naa_ieee(se_dev, &tmp_dev_wwn[0]);
75 
76 	rc = memcmp(&tmp_dev_wwn[0], info->dev_wwn, XCOPY_NAA_IEEE_REGEX_LEN);
77 	if (rc != 0)
78 		return 0;
79 
80 	info->found_dev = se_dev;
81 	pr_debug("XCOPY 0xe4: located se_dev: %p\n", se_dev);
82 
83 	rc = target_depend_item(&se_dev->dev_group.cg_item);
84 	if (rc != 0) {
85 		pr_err("configfs_depend_item attempt failed: %d for se_dev: %p\n",
86 		       rc, se_dev);
87 		return rc;
88 	}
89 
90 	pr_debug("Called configfs_depend_item for se_dev: %p se_dev->se_dev_group: %p\n",
91 		 se_dev, &se_dev->dev_group);
92 	return 1;
93 }
94 
95 static int target_xcopy_locate_se_dev_e4(const unsigned char *dev_wwn,
96 					struct se_device **found_dev)
97 {
98 	struct xcopy_dev_search_info info;
99 	int ret;
100 
101 	memset(&info, 0, sizeof(info));
102 	info.dev_wwn = dev_wwn;
103 
104 	ret = target_for_each_device(target_xcopy_locate_se_dev_e4_iter, &info);
105 	if (ret == 1) {
106 		*found_dev = info.found_dev;
107 		return 0;
108 	} else {
109 		pr_debug_ratelimited("Unable to locate 0xe4 descriptor for EXTENDED_COPY\n");
110 		return -EINVAL;
111 	}
112 }
113 
114 static int target_xcopy_parse_tiddesc_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
115 				unsigned char *p, unsigned short cscd_index)
116 {
117 	unsigned char *desc = p;
118 	unsigned short ript;
119 	u8 desig_len;
120 	/*
121 	 * Extract RELATIVE INITIATOR PORT IDENTIFIER
122 	 */
123 	ript = get_unaligned_be16(&desc[2]);
124 	pr_debug("XCOPY 0xe4: RELATIVE INITIATOR PORT IDENTIFIER: %hu\n", ript);
125 	/*
126 	 * Check for supported code set, association, and designator type
127 	 */
128 	if ((desc[4] & 0x0f) != 0x1) {
129 		pr_err("XCOPY 0xe4: code set of non binary type not supported\n");
130 		return -EINVAL;
131 	}
132 	if ((desc[5] & 0x30) != 0x00) {
133 		pr_err("XCOPY 0xe4: association other than LUN not supported\n");
134 		return -EINVAL;
135 	}
136 	if ((desc[5] & 0x0f) != 0x3) {
137 		pr_err("XCOPY 0xe4: designator type unsupported: 0x%02x\n",
138 				(desc[5] & 0x0f));
139 		return -EINVAL;
140 	}
141 	/*
142 	 * Check for matching 16 byte length for NAA IEEE Registered Extended
143 	 * Assigned designator
144 	 */
145 	desig_len = desc[7];
146 	if (desig_len != 16) {
147 		pr_err("XCOPY 0xe4: invalid desig_len: %d\n", (int)desig_len);
148 		return -EINVAL;
149 	}
150 	pr_debug("XCOPY 0xe4: desig_len: %d\n", (int)desig_len);
151 	/*
152 	 * Check for NAA IEEE Registered Extended Assigned header..
153 	 */
154 	if ((desc[8] & 0xf0) != 0x60) {
155 		pr_err("XCOPY 0xe4: Unsupported DESIGNATOR TYPE: 0x%02x\n",
156 					(desc[8] & 0xf0));
157 		return -EINVAL;
158 	}
159 
160 	if (cscd_index != xop->stdi && cscd_index != xop->dtdi) {
161 		pr_debug("XCOPY 0xe4: ignoring CSCD entry %d - neither src nor "
162 			 "dest\n", cscd_index);
163 		return 0;
164 	}
165 
166 	if (cscd_index == xop->stdi) {
167 		memcpy(&xop->src_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
168 		/*
169 		 * Determine if the source designator matches the local device
170 		 */
171 		if (!memcmp(&xop->local_dev_wwn[0], &xop->src_tid_wwn[0],
172 				XCOPY_NAA_IEEE_REGEX_LEN)) {
173 			xop->op_origin = XCOL_SOURCE_RECV_OP;
174 			xop->src_dev = se_cmd->se_dev;
175 			pr_debug("XCOPY 0xe4: Set xop->src_dev %p from source"
176 					" received xop\n", xop->src_dev);
177 		}
178 	}
179 
180 	if (cscd_index == xop->dtdi) {
181 		memcpy(&xop->dst_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
182 		/*
183 		 * Determine if the destination designator matches the local
184 		 * device. If @cscd_index corresponds to both source (stdi) and
185 		 * destination (dtdi), or dtdi comes after stdi, then
186 		 * XCOL_DEST_RECV_OP wins.
187 		 */
188 		if (!memcmp(&xop->local_dev_wwn[0], &xop->dst_tid_wwn[0],
189 				XCOPY_NAA_IEEE_REGEX_LEN)) {
190 			xop->op_origin = XCOL_DEST_RECV_OP;
191 			xop->dst_dev = se_cmd->se_dev;
192 			pr_debug("XCOPY 0xe4: Set xop->dst_dev: %p from destination"
193 				" received xop\n", xop->dst_dev);
194 		}
195 	}
196 
197 	return 0;
198 }
199 
200 static int target_xcopy_parse_target_descriptors(struct se_cmd *se_cmd,
201 				struct xcopy_op *xop, unsigned char *p,
202 				unsigned short tdll, sense_reason_t *sense_ret)
203 {
204 	struct se_device *local_dev = se_cmd->se_dev;
205 	unsigned char *desc = p;
206 	int offset = tdll % XCOPY_TARGET_DESC_LEN, rc;
207 	unsigned short cscd_index = 0;
208 	unsigned short start = 0;
209 
210 	*sense_ret = TCM_INVALID_PARAMETER_LIST;
211 
212 	if (offset != 0) {
213 		pr_err("XCOPY target descriptor list length is not"
214 			" multiple of %d\n", XCOPY_TARGET_DESC_LEN);
215 		*sense_ret = TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE;
216 		return -EINVAL;
217 	}
218 	if (tdll > RCR_OP_MAX_TARGET_DESC_COUNT * XCOPY_TARGET_DESC_LEN) {
219 		pr_err("XCOPY target descriptor supports a maximum"
220 			" two src/dest descriptors, tdll: %hu too large..\n", tdll);
221 		/* spc4r37 6.4.3.4 CSCD DESCRIPTOR LIST LENGTH field */
222 		*sense_ret = TCM_TOO_MANY_TARGET_DESCS;
223 		return -EINVAL;
224 	}
225 	/*
226 	 * Generate an IEEE Registered Extended designator based upon the
227 	 * se_device the XCOPY was received upon..
228 	 */
229 	memset(&xop->local_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
230 	target_xcopy_gen_naa_ieee(local_dev, &xop->local_dev_wwn[0]);
231 
232 	while (start < tdll) {
233 		/*
234 		 * Check target descriptor identification with 0xE4 type, and
235 		 * compare the current index with the CSCD descriptor IDs in
236 		 * the segment descriptor. Use VPD 0x83 WWPN matching ..
237 		 */
238 		switch (desc[0]) {
239 		case 0xe4:
240 			rc = target_xcopy_parse_tiddesc_e4(se_cmd, xop,
241 							&desc[0], cscd_index);
242 			if (rc != 0)
243 				goto out;
244 			start += XCOPY_TARGET_DESC_LEN;
245 			desc += XCOPY_TARGET_DESC_LEN;
246 			cscd_index++;
247 			break;
248 		default:
249 			pr_err("XCOPY unsupported descriptor type code:"
250 					" 0x%02x\n", desc[0]);
251 			*sense_ret = TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE;
252 			goto out;
253 		}
254 	}
255 
256 	switch (xop->op_origin) {
257 	case XCOL_SOURCE_RECV_OP:
258 		rc = target_xcopy_locate_se_dev_e4(xop->dst_tid_wwn,
259 						&xop->dst_dev);
260 		break;
261 	case XCOL_DEST_RECV_OP:
262 		rc = target_xcopy_locate_se_dev_e4(xop->src_tid_wwn,
263 						&xop->src_dev);
264 		break;
265 	default:
266 		pr_err("XCOPY CSCD descriptor IDs not found in CSCD list - "
267 			"stdi: %hu dtdi: %hu\n", xop->stdi, xop->dtdi);
268 		rc = -EINVAL;
269 		break;
270 	}
271 	/*
272 	 * If a matching IEEE NAA 0x83 descriptor for the requested device
273 	 * is not located on this node, return COPY_ABORTED with ASQ/ASQC
274 	 * 0x0d/0x02 - COPY_TARGET_DEVICE_NOT_REACHABLE to request the
275 	 * initiator to fall back to normal copy method.
276 	 */
277 	if (rc < 0) {
278 		*sense_ret = TCM_COPY_TARGET_DEVICE_NOT_REACHABLE;
279 		goto out;
280 	}
281 
282 	pr_debug("XCOPY TGT desc: Source dev: %p NAA IEEE WWN: 0x%16phN\n",
283 		 xop->src_dev, &xop->src_tid_wwn[0]);
284 	pr_debug("XCOPY TGT desc: Dest dev: %p NAA IEEE WWN: 0x%16phN\n",
285 		 xop->dst_dev, &xop->dst_tid_wwn[0]);
286 
287 	return cscd_index;
288 
289 out:
290 	return -EINVAL;
291 }
292 
293 static int target_xcopy_parse_segdesc_02(struct se_cmd *se_cmd, struct xcopy_op *xop,
294 					unsigned char *p)
295 {
296 	unsigned char *desc = p;
297 	int dc = (desc[1] & 0x02);
298 	unsigned short desc_len;
299 
300 	desc_len = get_unaligned_be16(&desc[2]);
301 	if (desc_len != 0x18) {
302 		pr_err("XCOPY segment desc 0x02: Illegal desc_len:"
303 				" %hu\n", desc_len);
304 		return -EINVAL;
305 	}
306 
307 	xop->stdi = get_unaligned_be16(&desc[4]);
308 	xop->dtdi = get_unaligned_be16(&desc[6]);
309 
310 	if (xop->stdi > XCOPY_CSCD_DESC_ID_LIST_OFF_MAX ||
311 	    xop->dtdi > XCOPY_CSCD_DESC_ID_LIST_OFF_MAX) {
312 		pr_err("XCOPY segment desc 0x02: unsupported CSCD ID > 0x%x; stdi: %hu dtdi: %hu\n",
313 			XCOPY_CSCD_DESC_ID_LIST_OFF_MAX, xop->stdi, xop->dtdi);
314 		return -EINVAL;
315 	}
316 
317 	pr_debug("XCOPY seg desc 0x02: desc_len: %hu stdi: %hu dtdi: %hu, DC: %d\n",
318 		desc_len, xop->stdi, xop->dtdi, dc);
319 
320 	xop->nolb = get_unaligned_be16(&desc[10]);
321 	xop->src_lba = get_unaligned_be64(&desc[12]);
322 	xop->dst_lba = get_unaligned_be64(&desc[20]);
323 	pr_debug("XCOPY seg desc 0x02: nolb: %hu src_lba: %llu dst_lba: %llu\n",
324 		xop->nolb, (unsigned long long)xop->src_lba,
325 		(unsigned long long)xop->dst_lba);
326 
327 	if (dc != 0) {
328 		xop->dbl = get_unaligned_be24(&desc[29]);
329 
330 		pr_debug("XCOPY seg desc 0x02: DC=1 w/ dbl: %u\n", xop->dbl);
331 	}
332 	return 0;
333 }
334 
335 static int target_xcopy_parse_segment_descriptors(struct se_cmd *se_cmd,
336 				struct xcopy_op *xop, unsigned char *p,
337 				unsigned int sdll, sense_reason_t *sense_ret)
338 {
339 	unsigned char *desc = p;
340 	unsigned int start = 0;
341 	int offset = sdll % XCOPY_SEGMENT_DESC_LEN, rc, ret = 0;
342 
343 	*sense_ret = TCM_INVALID_PARAMETER_LIST;
344 
345 	if (offset != 0) {
346 		pr_err("XCOPY segment descriptor list length is not"
347 			" multiple of %d\n", XCOPY_SEGMENT_DESC_LEN);
348 		*sense_ret = TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE;
349 		return -EINVAL;
350 	}
351 	if (sdll > RCR_OP_MAX_SG_DESC_COUNT * XCOPY_SEGMENT_DESC_LEN) {
352 		pr_err("XCOPY supports %u segment descriptor(s), sdll: %u too"
353 			" large..\n", RCR_OP_MAX_SG_DESC_COUNT, sdll);
354 		/* spc4r37 6.4.3.5 SEGMENT DESCRIPTOR LIST LENGTH field */
355 		*sense_ret = TCM_TOO_MANY_SEGMENT_DESCS;
356 		return -EINVAL;
357 	}
358 
359 	while (start < sdll) {
360 		/*
361 		 * Check segment descriptor type code for block -> block
362 		 */
363 		switch (desc[0]) {
364 		case 0x02:
365 			rc = target_xcopy_parse_segdesc_02(se_cmd, xop, desc);
366 			if (rc < 0)
367 				goto out;
368 
369 			ret++;
370 			start += XCOPY_SEGMENT_DESC_LEN;
371 			desc += XCOPY_SEGMENT_DESC_LEN;
372 			break;
373 		default:
374 			pr_err("XCOPY unsupported segment descriptor"
375 				"type: 0x%02x\n", desc[0]);
376 			*sense_ret = TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE;
377 			goto out;
378 		}
379 	}
380 
381 	return ret;
382 
383 out:
384 	return -EINVAL;
385 }
386 
387 /*
388  * Start xcopy_pt ops
389  */
390 
391 struct xcopy_pt_cmd {
392 	struct se_cmd se_cmd;
393 	struct completion xpt_passthrough_sem;
394 	unsigned char sense_buffer[TRANSPORT_SENSE_BUFFER];
395 };
396 
397 struct se_portal_group xcopy_pt_tpg;
398 static struct se_session xcopy_pt_sess;
399 static struct se_node_acl xcopy_pt_nacl;
400 
401 static int xcopy_pt_get_cmd_state(struct se_cmd *se_cmd)
402 {
403         return 0;
404 }
405 
406 static void xcopy_pt_undepend_remotedev(struct xcopy_op *xop)
407 {
408 	struct se_device *remote_dev;
409 
410 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
411 		remote_dev = xop->dst_dev;
412 	else
413 		remote_dev = xop->src_dev;
414 
415 	pr_debug("Calling configfs_undepend_item for"
416 		  " remote_dev: %p remote_dev->dev_group: %p\n",
417 		  remote_dev, &remote_dev->dev_group.cg_item);
418 
419 	target_undepend_item(&remote_dev->dev_group.cg_item);
420 }
421 
422 static void xcopy_pt_release_cmd(struct se_cmd *se_cmd)
423 {
424 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
425 				struct xcopy_pt_cmd, se_cmd);
426 
427 	kfree(xpt_cmd);
428 }
429 
430 static int xcopy_pt_check_stop_free(struct se_cmd *se_cmd)
431 {
432 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
433 				struct xcopy_pt_cmd, se_cmd);
434 
435 	complete(&xpt_cmd->xpt_passthrough_sem);
436 	return 0;
437 }
438 
439 static int xcopy_pt_write_pending(struct se_cmd *se_cmd)
440 {
441 	return 0;
442 }
443 
444 static int xcopy_pt_queue_data_in(struct se_cmd *se_cmd)
445 {
446 	return 0;
447 }
448 
449 static int xcopy_pt_queue_status(struct se_cmd *se_cmd)
450 {
451 	return 0;
452 }
453 
454 static const struct target_core_fabric_ops xcopy_pt_tfo = {
455 	.fabric_name		= "xcopy-pt",
456 	.get_cmd_state		= xcopy_pt_get_cmd_state,
457 	.release_cmd		= xcopy_pt_release_cmd,
458 	.check_stop_free	= xcopy_pt_check_stop_free,
459 	.write_pending		= xcopy_pt_write_pending,
460 	.queue_data_in		= xcopy_pt_queue_data_in,
461 	.queue_status		= xcopy_pt_queue_status,
462 };
463 
464 /*
465  * End xcopy_pt_ops
466  */
467 
468 int target_xcopy_setup_pt(void)
469 {
470 	int ret;
471 
472 	xcopy_wq = alloc_workqueue("xcopy_wq", WQ_MEM_RECLAIM, 0);
473 	if (!xcopy_wq) {
474 		pr_err("Unable to allocate xcopy_wq\n");
475 		return -ENOMEM;
476 	}
477 
478 	memset(&xcopy_pt_tpg, 0, sizeof(struct se_portal_group));
479 	INIT_LIST_HEAD(&xcopy_pt_tpg.se_tpg_node);
480 	INIT_LIST_HEAD(&xcopy_pt_tpg.acl_node_list);
481 	INIT_LIST_HEAD(&xcopy_pt_tpg.tpg_sess_list);
482 
483 	xcopy_pt_tpg.se_tpg_tfo = &xcopy_pt_tfo;
484 
485 	memset(&xcopy_pt_nacl, 0, sizeof(struct se_node_acl));
486 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_list);
487 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_sess_list);
488 	memset(&xcopy_pt_sess, 0, sizeof(struct se_session));
489 	ret = transport_init_session(&xcopy_pt_sess);
490 	if (ret < 0)
491 		return ret;
492 
493 	xcopy_pt_nacl.se_tpg = &xcopy_pt_tpg;
494 	xcopy_pt_nacl.nacl_sess = &xcopy_pt_sess;
495 
496 	xcopy_pt_sess.se_tpg = &xcopy_pt_tpg;
497 	xcopy_pt_sess.se_node_acl = &xcopy_pt_nacl;
498 
499 	return 0;
500 }
501 
502 void target_xcopy_release_pt(void)
503 {
504 	if (xcopy_wq)
505 		destroy_workqueue(xcopy_wq);
506 }
507 
508 /*
509  * target_xcopy_setup_pt_cmd - set up a pass-through command
510  * @xpt_cmd:	 Data structure to initialize.
511  * @xop:	 Describes the XCOPY operation received from an initiator.
512  * @se_dev:	 Backend device to associate with @xpt_cmd if
513  *		 @remote_port == true.
514  * @cdb:	 SCSI CDB to be copied into @xpt_cmd.
515  * @remote_port: If false, use the LUN through which the XCOPY command has
516  *		 been received. If true, use @se_dev->xcopy_lun.
517  * @alloc_mem:	 Whether or not to allocate an SGL list.
518  *
519  * Set up a SCSI command (READ or WRITE) that will be used to execute an
520  * XCOPY command.
521  */
522 static int target_xcopy_setup_pt_cmd(
523 	struct xcopy_pt_cmd *xpt_cmd,
524 	struct xcopy_op *xop,
525 	struct se_device *se_dev,
526 	unsigned char *cdb,
527 	bool remote_port,
528 	bool alloc_mem)
529 {
530 	struct se_cmd *cmd = &xpt_cmd->se_cmd;
531 	sense_reason_t sense_rc;
532 	int ret = 0, rc;
533 
534 	/*
535 	 * Setup LUN+port to honor reservations based upon xop->op_origin for
536 	 * X-COPY PUSH or X-COPY PULL based upon where the CDB was received.
537 	 */
538 	if (remote_port) {
539 		cmd->se_lun = &se_dev->xcopy_lun;
540 		cmd->se_dev = se_dev;
541 	} else {
542 		cmd->se_lun = xop->xop_se_cmd->se_lun;
543 		cmd->se_dev = xop->xop_se_cmd->se_dev;
544 	}
545 	cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
546 
547 	cmd->tag = 0;
548 	sense_rc = target_setup_cmd_from_cdb(cmd, cdb);
549 	if (sense_rc) {
550 		ret = -EINVAL;
551 		goto out;
552 	}
553 
554 	if (alloc_mem) {
555 		rc = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
556 				      cmd->data_length, false, false);
557 		if (rc < 0) {
558 			ret = rc;
559 			goto out;
560 		}
561 		/*
562 		 * Set this bit so that transport_free_pages() allows the
563 		 * caller to release SGLs + physical memory allocated by
564 		 * transport_generic_get_mem()..
565 		 */
566 		cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
567 	} else {
568 		/*
569 		 * Here the previously allocated SGLs for the internal READ
570 		 * are mapped zero-copy to the internal WRITE.
571 		 */
572 		sense_rc = transport_generic_map_mem_to_cmd(cmd,
573 					xop->xop_data_sg, xop->xop_data_nents,
574 					NULL, 0);
575 		if (sense_rc) {
576 			ret = -EINVAL;
577 			goto out;
578 		}
579 
580 		pr_debug("Setup PASSTHROUGH_NOALLOC t_data_sg: %p t_data_nents:"
581 			 " %u\n", cmd->t_data_sg, cmd->t_data_nents);
582 	}
583 
584 	return 0;
585 
586 out:
587 	return ret;
588 }
589 
590 static int target_xcopy_issue_pt_cmd(struct xcopy_pt_cmd *xpt_cmd)
591 {
592 	struct se_cmd *se_cmd = &xpt_cmd->se_cmd;
593 	sense_reason_t sense_rc;
594 
595 	sense_rc = transport_generic_new_cmd(se_cmd);
596 	if (sense_rc)
597 		return -EINVAL;
598 
599 	if (se_cmd->data_direction == DMA_TO_DEVICE)
600 		target_execute_cmd(se_cmd);
601 
602 	wait_for_completion_interruptible(&xpt_cmd->xpt_passthrough_sem);
603 
604 	pr_debug("target_xcopy_issue_pt_cmd(): SCSI status: 0x%02x\n",
605 			se_cmd->scsi_status);
606 
607 	return (se_cmd->scsi_status) ? -EINVAL : 0;
608 }
609 
610 static int target_xcopy_read_source(
611 	struct se_cmd *ec_cmd,
612 	struct xcopy_op *xop,
613 	struct se_device *src_dev,
614 	sector_t src_lba,
615 	u32 src_sectors)
616 {
617 	struct xcopy_pt_cmd *xpt_cmd;
618 	struct se_cmd *se_cmd;
619 	u32 length = (src_sectors * src_dev->dev_attrib.block_size);
620 	int rc;
621 	unsigned char cdb[16];
622 	bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);
623 
624 	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
625 	if (!xpt_cmd) {
626 		pr_err("Unable to allocate xcopy_pt_cmd\n");
627 		return -ENOMEM;
628 	}
629 	init_completion(&xpt_cmd->xpt_passthrough_sem);
630 	se_cmd = &xpt_cmd->se_cmd;
631 
632 	memset(&cdb[0], 0, 16);
633 	cdb[0] = READ_16;
634 	put_unaligned_be64(src_lba, &cdb[2]);
635 	put_unaligned_be32(src_sectors, &cdb[10]);
636 	pr_debug("XCOPY: Built READ_16: LBA: %llu Sectors: %u Length: %u\n",
637 		(unsigned long long)src_lba, src_sectors, length);
638 
639 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, length,
640 			      DMA_FROM_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
641 	xop->src_pt_cmd = xpt_cmd;
642 
643 	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, src_dev, &cdb[0],
644 				remote_port, true);
645 	if (rc < 0) {
646 		ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;
647 		transport_generic_free_cmd(se_cmd, 0);
648 		return rc;
649 	}
650 
651 	xop->xop_data_sg = se_cmd->t_data_sg;
652 	xop->xop_data_nents = se_cmd->t_data_nents;
653 	pr_debug("XCOPY-READ: Saved xop->xop_data_sg: %p, num: %u for READ"
654 		" memory\n", xop->xop_data_sg, xop->xop_data_nents);
655 
656 	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
657 	if (rc < 0) {
658 		ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;
659 		transport_generic_free_cmd(se_cmd, 0);
660 		return rc;
661 	}
662 	/*
663 	 * Clear off the allocated t_data_sg, that has been saved for
664 	 * zero-copy WRITE submission reuse in struct xcopy_op..
665 	 */
666 	se_cmd->t_data_sg = NULL;
667 	se_cmd->t_data_nents = 0;
668 
669 	return 0;
670 }
671 
672 static int target_xcopy_write_destination(
673 	struct se_cmd *ec_cmd,
674 	struct xcopy_op *xop,
675 	struct se_device *dst_dev,
676 	sector_t dst_lba,
677 	u32 dst_sectors)
678 {
679 	struct xcopy_pt_cmd *xpt_cmd;
680 	struct se_cmd *se_cmd;
681 	u32 length = (dst_sectors * dst_dev->dev_attrib.block_size);
682 	int rc;
683 	unsigned char cdb[16];
684 	bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);
685 
686 	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
687 	if (!xpt_cmd) {
688 		pr_err("Unable to allocate xcopy_pt_cmd\n");
689 		return -ENOMEM;
690 	}
691 	init_completion(&xpt_cmd->xpt_passthrough_sem);
692 	se_cmd = &xpt_cmd->se_cmd;
693 
694 	memset(&cdb[0], 0, 16);
695 	cdb[0] = WRITE_16;
696 	put_unaligned_be64(dst_lba, &cdb[2]);
697 	put_unaligned_be32(dst_sectors, &cdb[10]);
698 	pr_debug("XCOPY: Built WRITE_16: LBA: %llu Sectors: %u Length: %u\n",
699 		(unsigned long long)dst_lba, dst_sectors, length);
700 
701 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, length,
702 			      DMA_TO_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
703 	xop->dst_pt_cmd = xpt_cmd;
704 
705 	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, dst_dev, &cdb[0],
706 				remote_port, false);
707 	if (rc < 0) {
708 		struct se_cmd *src_cmd = &xop->src_pt_cmd->se_cmd;
709 		ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;
710 		/*
711 		 * If the failure happened before the t_mem_list hand-off in
712 		 * target_xcopy_setup_pt_cmd(), Reset memory + clear flag so that
713 		 * core releases this memory on error during X-COPY WRITE I/O.
714 		 */
715 		src_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
716 		src_cmd->t_data_sg = xop->xop_data_sg;
717 		src_cmd->t_data_nents = xop->xop_data_nents;
718 
719 		transport_generic_free_cmd(se_cmd, 0);
720 		return rc;
721 	}
722 
723 	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
724 	if (rc < 0) {
725 		ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;
726 		se_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
727 		transport_generic_free_cmd(se_cmd, 0);
728 		return rc;
729 	}
730 
731 	return 0;
732 }
733 
734 static void target_xcopy_do_work(struct work_struct *work)
735 {
736 	struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
737 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
738 	struct se_device *src_dev, *dst_dev;
739 	sector_t src_lba, dst_lba, end_lba;
740 	unsigned int max_sectors;
741 	int rc = 0;
742 	unsigned short nolb, cur_nolb, max_nolb, copied_nolb = 0;
743 
744 	if (target_parse_xcopy_cmd(xop) != TCM_NO_SENSE)
745 		goto err_free;
746 
747 	if (WARN_ON_ONCE(!xop->src_dev) || WARN_ON_ONCE(!xop->dst_dev))
748 		goto err_free;
749 
750 	src_dev = xop->src_dev;
751 	dst_dev = xop->dst_dev;
752 	src_lba = xop->src_lba;
753 	dst_lba = xop->dst_lba;
754 	nolb = xop->nolb;
755 	end_lba = src_lba + nolb;
756 	/*
757 	 * Break up XCOPY I/O into hw_max_sectors sized I/O based on the
758 	 * smallest max_sectors between src_dev + dev_dev, or
759 	 */
760 	max_sectors = min(src_dev->dev_attrib.hw_max_sectors,
761 			  dst_dev->dev_attrib.hw_max_sectors);
762 	max_sectors = min_t(u32, max_sectors, XCOPY_MAX_SECTORS);
763 
764 	max_nolb = min_t(u16, max_sectors, ((u16)(~0U)));
765 
766 	pr_debug("target_xcopy_do_work: nolb: %hu, max_nolb: %hu end_lba: %llu\n",
767 			nolb, max_nolb, (unsigned long long)end_lba);
768 	pr_debug("target_xcopy_do_work: Starting src_lba: %llu, dst_lba: %llu\n",
769 			(unsigned long long)src_lba, (unsigned long long)dst_lba);
770 
771 	while (src_lba < end_lba) {
772 		cur_nolb = min(nolb, max_nolb);
773 
774 		pr_debug("target_xcopy_do_work: Calling read src_dev: %p src_lba: %llu,"
775 			" cur_nolb: %hu\n", src_dev, (unsigned long long)src_lba, cur_nolb);
776 
777 		rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_nolb);
778 		if (rc < 0)
779 			goto out;
780 
781 		src_lba += cur_nolb;
782 		pr_debug("target_xcopy_do_work: Incremented READ src_lba to %llu\n",
783 				(unsigned long long)src_lba);
784 
785 		pr_debug("target_xcopy_do_work: Calling write dst_dev: %p dst_lba: %llu,"
786 			" cur_nolb: %hu\n", dst_dev, (unsigned long long)dst_lba, cur_nolb);
787 
788 		rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
789 						dst_lba, cur_nolb);
790 		if (rc < 0) {
791 			transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
792 			goto out;
793 		}
794 
795 		dst_lba += cur_nolb;
796 		pr_debug("target_xcopy_do_work: Incremented WRITE dst_lba to %llu\n",
797 				(unsigned long long)dst_lba);
798 
799 		copied_nolb += cur_nolb;
800 		nolb -= cur_nolb;
801 
802 		transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
803 		xop->dst_pt_cmd->se_cmd.se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
804 
805 		transport_generic_free_cmd(&xop->dst_pt_cmd->se_cmd, 0);
806 	}
807 
808 	xcopy_pt_undepend_remotedev(xop);
809 	kfree(xop);
810 
811 	pr_debug("target_xcopy_do_work: Final src_lba: %llu, dst_lba: %llu\n",
812 		(unsigned long long)src_lba, (unsigned long long)dst_lba);
813 	pr_debug("target_xcopy_do_work: Blocks copied: %hu, Bytes Copied: %u\n",
814 		copied_nolb, copied_nolb * dst_dev->dev_attrib.block_size);
815 
816 	pr_debug("target_xcopy_do_work: Setting X-COPY GOOD status -> sending response\n");
817 	target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
818 	return;
819 
820 out:
821 	xcopy_pt_undepend_remotedev(xop);
822 
823 err_free:
824 	kfree(xop);
825 	/*
826 	 * Don't override an error scsi status if it has already been set
827 	 */
828 	if (ec_cmd->scsi_status == SAM_STAT_GOOD) {
829 		pr_warn_ratelimited("target_xcopy_do_work: rc: %d, Setting X-COPY"
830 			" CHECK_CONDITION -> sending response\n", rc);
831 		ec_cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
832 	}
833 	target_complete_cmd(ec_cmd, ec_cmd->scsi_status);
834 }
835 
836 /*
837  * Returns TCM_NO_SENSE upon success or a sense code != TCM_NO_SENSE if parsing
838  * fails.
839  */
840 static sense_reason_t target_parse_xcopy_cmd(struct xcopy_op *xop)
841 {
842 	struct se_cmd *se_cmd = xop->xop_se_cmd;
843 	unsigned char *p = NULL, *seg_desc;
844 	unsigned int list_id, list_id_usage, sdll, inline_dl;
845 	sense_reason_t ret = TCM_INVALID_PARAMETER_LIST;
846 	int rc;
847 	unsigned short tdll;
848 
849 	p = transport_kmap_data_sg(se_cmd);
850 	if (!p) {
851 		pr_err("transport_kmap_data_sg() failed in target_do_xcopy\n");
852 		return TCM_OUT_OF_RESOURCES;
853 	}
854 
855 	list_id = p[0];
856 	list_id_usage = (p[1] & 0x18) >> 3;
857 
858 	/*
859 	 * Determine TARGET DESCRIPTOR LIST LENGTH + SEGMENT DESCRIPTOR LIST LENGTH
860 	 */
861 	tdll = get_unaligned_be16(&p[2]);
862 	sdll = get_unaligned_be32(&p[8]);
863 	if (tdll + sdll > RCR_OP_MAX_DESC_LIST_LEN) {
864 		pr_err("XCOPY descriptor list length %u exceeds maximum %u\n",
865 		       tdll + sdll, RCR_OP_MAX_DESC_LIST_LEN);
866 		ret = TCM_PARAMETER_LIST_LENGTH_ERROR;
867 		goto out;
868 	}
869 
870 	inline_dl = get_unaligned_be32(&p[12]);
871 	if (inline_dl != 0) {
872 		pr_err("XCOPY with non zero inline data length\n");
873 		goto out;
874 	}
875 
876 	if (se_cmd->data_length < (XCOPY_HDR_LEN + tdll + sdll + inline_dl)) {
877 		pr_err("XCOPY parameter truncation: data length %u too small "
878 			"for tdll: %hu sdll: %u inline_dl: %u\n",
879 			se_cmd->data_length, tdll, sdll, inline_dl);
880 		ret = TCM_PARAMETER_LIST_LENGTH_ERROR;
881 		goto out;
882 	}
883 
884 	pr_debug("Processing XCOPY with list_id: 0x%02x list_id_usage: 0x%02x"
885 		" tdll: %hu sdll: %u inline_dl: %u\n", list_id, list_id_usage,
886 		tdll, sdll, inline_dl);
887 
888 	/*
889 	 * skip over the target descriptors until segment descriptors
890 	 * have been passed - CSCD ids are needed to determine src and dest.
891 	 */
892 	seg_desc = &p[16] + tdll;
893 
894 	rc = target_xcopy_parse_segment_descriptors(se_cmd, xop, seg_desc,
895 						    sdll, &ret);
896 	if (rc <= 0)
897 		goto out;
898 
899 	pr_debug("XCOPY: Processed %d segment descriptors, length: %u\n", rc,
900 				rc * XCOPY_SEGMENT_DESC_LEN);
901 
902 	rc = target_xcopy_parse_target_descriptors(se_cmd, xop, &p[16], tdll, &ret);
903 	if (rc <= 0)
904 		goto out;
905 
906 	if (xop->src_dev->dev_attrib.block_size !=
907 	    xop->dst_dev->dev_attrib.block_size) {
908 		pr_err("XCOPY: Non matching src_dev block_size: %u + dst_dev"
909 		       " block_size: %u currently unsupported\n",
910 			xop->src_dev->dev_attrib.block_size,
911 			xop->dst_dev->dev_attrib.block_size);
912 		xcopy_pt_undepend_remotedev(xop);
913 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
914 		goto out;
915 	}
916 
917 	pr_debug("XCOPY: Processed %d target descriptors, length: %u\n", rc,
918 				rc * XCOPY_TARGET_DESC_LEN);
919 	transport_kunmap_data_sg(se_cmd);
920 	return TCM_NO_SENSE;
921 
922 out:
923 	if (p)
924 		transport_kunmap_data_sg(se_cmd);
925 	return ret;
926 }
927 
928 sense_reason_t target_do_xcopy(struct se_cmd *se_cmd)
929 {
930 	struct se_device *dev = se_cmd->se_dev;
931 	struct xcopy_op *xop;
932 	unsigned int sa;
933 
934 	if (!dev->dev_attrib.emulate_3pc) {
935 		pr_err("EXTENDED_COPY operation explicitly disabled\n");
936 		return TCM_UNSUPPORTED_SCSI_OPCODE;
937 	}
938 
939 	sa = se_cmd->t_task_cdb[1] & 0x1f;
940 	if (sa != 0x00) {
941 		pr_err("EXTENDED_COPY(LID4) not supported\n");
942 		return TCM_UNSUPPORTED_SCSI_OPCODE;
943 	}
944 
945 	if (se_cmd->data_length == 0) {
946 		target_complete_cmd(se_cmd, SAM_STAT_GOOD);
947 		return TCM_NO_SENSE;
948 	}
949 	if (se_cmd->data_length < XCOPY_HDR_LEN) {
950 		pr_err("XCOPY parameter truncation: length %u < hdr_len %u\n",
951 				se_cmd->data_length, XCOPY_HDR_LEN);
952 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
953 	}
954 
955 	xop = kzalloc(sizeof(struct xcopy_op), GFP_KERNEL);
956 	if (!xop)
957 		goto err;
958 	xop->xop_se_cmd = se_cmd;
959 	INIT_WORK(&xop->xop_work, target_xcopy_do_work);
960 	if (WARN_ON_ONCE(!queue_work(xcopy_wq, &xop->xop_work)))
961 		goto free;
962 	return TCM_NO_SENSE;
963 
964 free:
965 	kfree(xop);
966 
967 err:
968 	return TCM_OUT_OF_RESOURCES;
969 }
970 
971 static sense_reason_t target_rcr_operating_parameters(struct se_cmd *se_cmd)
972 {
973 	unsigned char *p;
974 
975 	p = transport_kmap_data_sg(se_cmd);
976 	if (!p) {
977 		pr_err("transport_kmap_data_sg failed in"
978 		       " target_rcr_operating_parameters\n");
979 		return TCM_OUT_OF_RESOURCES;
980 	}
981 
982 	if (se_cmd->data_length < 54) {
983 		pr_err("Receive Copy Results Op Parameters length"
984 		       " too small: %u\n", se_cmd->data_length);
985 		transport_kunmap_data_sg(se_cmd);
986 		return TCM_INVALID_CDB_FIELD;
987 	}
988 	/*
989 	 * Set SNLID=1 (Supports no List ID)
990 	 */
991 	p[4] = 0x1;
992 	/*
993 	 * MAXIMUM TARGET DESCRIPTOR COUNT
994 	 */
995 	put_unaligned_be16(RCR_OP_MAX_TARGET_DESC_COUNT, &p[8]);
996 	/*
997 	 * MAXIMUM SEGMENT DESCRIPTOR COUNT
998 	 */
999 	put_unaligned_be16(RCR_OP_MAX_SG_DESC_COUNT, &p[10]);
1000 	/*
1001 	 * MAXIMUM DESCRIPTOR LIST LENGTH
1002 	 */
1003 	put_unaligned_be32(RCR_OP_MAX_DESC_LIST_LEN, &p[12]);
1004 	/*
1005 	 * MAXIMUM SEGMENT LENGTH
1006 	 */
1007 	put_unaligned_be32(RCR_OP_MAX_SEGMENT_LEN, &p[16]);
1008 	/*
1009 	 * MAXIMUM INLINE DATA LENGTH for SA 0x04 (NOT SUPPORTED)
1010 	 */
1011 	put_unaligned_be32(0x0, &p[20]);
1012 	/*
1013 	 * HELD DATA LIMIT
1014 	 */
1015 	put_unaligned_be32(0x0, &p[24]);
1016 	/*
1017 	 * MAXIMUM STREAM DEVICE TRANSFER SIZE
1018 	 */
1019 	put_unaligned_be32(0x0, &p[28]);
1020 	/*
1021 	 * TOTAL CONCURRENT COPIES
1022 	 */
1023 	put_unaligned_be16(RCR_OP_TOTAL_CONCURR_COPIES, &p[34]);
1024 	/*
1025 	 * MAXIMUM CONCURRENT COPIES
1026 	 */
1027 	p[36] = RCR_OP_MAX_CONCURR_COPIES;
1028 	/*
1029 	 * DATA SEGMENT GRANULARITY (log 2)
1030 	 */
1031 	p[37] = RCR_OP_DATA_SEG_GRAN_LOG2;
1032 	/*
1033 	 * INLINE DATA GRANULARITY log 2)
1034 	 */
1035 	p[38] = RCR_OP_INLINE_DATA_GRAN_LOG2;
1036 	/*
1037 	 * HELD DATA GRANULARITY
1038 	 */
1039 	p[39] = RCR_OP_HELD_DATA_GRAN_LOG2;
1040 	/*
1041 	 * IMPLEMENTED DESCRIPTOR LIST LENGTH
1042 	 */
1043 	p[43] = 0x2;
1044 	/*
1045 	 * List of implemented descriptor type codes (ordered)
1046 	 */
1047 	p[44] = 0x02; /* Copy Block to Block device */
1048 	p[45] = 0xe4; /* Identification descriptor target descriptor */
1049 
1050 	/*
1051 	 * AVAILABLE DATA (n-3)
1052 	 */
1053 	put_unaligned_be32(42, &p[0]);
1054 
1055 	transport_kunmap_data_sg(se_cmd);
1056 	target_complete_cmd(se_cmd, GOOD);
1057 
1058 	return TCM_NO_SENSE;
1059 }
1060 
1061 sense_reason_t target_do_receive_copy_results(struct se_cmd *se_cmd)
1062 {
1063 	unsigned char *cdb = &se_cmd->t_task_cdb[0];
1064 	int sa = (cdb[1] & 0x1f), list_id = cdb[2];
1065 	sense_reason_t rc = TCM_NO_SENSE;
1066 
1067 	pr_debug("Entering target_do_receive_copy_results: SA: 0x%02x, List ID:"
1068 		" 0x%02x, AL: %u\n", sa, list_id, se_cmd->data_length);
1069 
1070 	if (list_id != 0) {
1071 		pr_err("Receive Copy Results with non zero list identifier"
1072 		       " not supported\n");
1073 		return TCM_INVALID_CDB_FIELD;
1074 	}
1075 
1076 	switch (sa) {
1077 	case RCR_SA_OPERATING_PARAMETERS:
1078 		rc = target_rcr_operating_parameters(se_cmd);
1079 		break;
1080 	case RCR_SA_COPY_STATUS:
1081 	case RCR_SA_RECEIVE_DATA:
1082 	case RCR_SA_FAILED_SEGMENT_DETAILS:
1083 	default:
1084 		pr_err("Unsupported SA for receive copy results: 0x%02x\n", sa);
1085 		return TCM_INVALID_CDB_FIELD;
1086 	}
1087 
1088 	return rc;
1089 }
1090